Suspension manufacturer RockShox assembled mountain bike journalists from all over the world in Durango, Colorado to unveil new product offerings for the 2011 model year. There were a whole range of things to see, and I’ll be breaking things down over a few articles, looking at front suspension, rear suspension and one product that deserves to be singled out (in my opinion). That product? The new RockShox Reverb height adjustable seatpost.
Height adjustable (HA) seatposts are nothing new. If you’ve been riding long enough, you’ll probably remember the Hite Rite, which gave you up to 4.5″ of height adjustment on your post. Sure, you had to undo the seatpost quick release while you were riding in order to lower or raise your post, but it did the trick. And they worked well enough for some people to continue using them until very recently (including a certain product developer / tester for RockShox parent company SRAM).
Fast forward about a decade or so from when the Hite Rite was introduced and you find a whole realm of height adjustable seatposts to choose from. There were two basic control mechanisms: a lever under the saddle that released a catch and allowed the post to move up or down, or a remote mechanism attached to a similar release via a cable. They worked to varying degrees of success, but the cable versions were always susceptable to contamination from the elements.
RockShox could have built a cable-activated HA post just to get into the market, but decided instead to do something different. Using the lessons learned when they developed remote hydraulically-activated damping controls for the new XX suspension forks, RockShox applied that same technology to seatposts and the Reverb was born.
The RockShox Reverb height-adjustable seatpost in all its glory. The hydraulic adjustment mechanism is in the head of the post.
The technical details
Reverb is a very functional piece of technology that takes advantage of design innovations that have been put into use in existing products. It basically functions like a travel-adjustable suspension fork, using an air / oil damping mechanism with an independent floating piston to control the height of the post.
Reverb guts, exposed. It’s not a particularly complicated system, but it works very well.
The post offers 125mm (5″) of height adjustability, controlled by a Xloc button mounted on the handlebar. Weight the seat, push and hold the button and the seat goes down. Ride as you normally would with your seat down. When you want the post to come back up, push the button and the saddle comes up all on its own. Yes, it’s that simple. You can also stop the post at any point in its travel range (also known as “infinite adjustment”).
The discrete clamp mounted lever for controlling post height. The barrel adjuster can be dialled in or out to speed up or slow down compression and rebound rates for the post.
The Reverb uses 2.5WT fork oil and can be bled with a RockShox Speed Lube kit. A triple-lipped energized sealing system is used to keep out contaminants, and a three-key anti-rotation system minimizes or eliminates side-to-side play in the post.
This is where the hydraulics enter the head of the post. It’s where oil flow – and height – are controlled
The shaft of the Reverb is made from 3D forged 7050 alloy, while the head is straight 7050 aluminum. Reverb is available in two lengths: 380mm and 420mm, and two diameters: 30.9mm and 31.6mm. There are 12° +/- of head angle adjustability, so it will work with most seat tube angles – as long as they’re not too extreme.
Weight is a claimed 515 grams (for a 380mm / 30.9mm post with the bar-mounted lever and 1300mm of hose). That puts it in exactly the same category as the 125mm KS i950-R post at 536g and lighter than the Crank Brothers Joplin-R with 4″ of travel at 590g. RockShox also says that the hydraulic cable is lighter than cable housing and a steel cable of the same length.
Close-up of the non-cable side of the head. It’s a standard two-bolt clamping system with indicators for saddle angle. The bleed port is also located on this side of the post head.
At this time, there is only one amount of travel available for the Reverb, and it only comes with a zero offset head. RockShox wanted to make the new post appealing to the largest number of riders possible right out of the gate, and the 5″ / zero offset version will do that. Developing a shorter-travel version will be as simple as putting in a bumper to limit travel.
Unlike most other HA posts, it’s possible to change the compression and rebound rates for the Reverb via the barrel adjuster on the remote lever, which controls the size of port holes in the oil flow valve in the seatpost head assembly. This is what RockShox product manager Jeremiah Boobar affectionately refers to as the “slap or tickle” feature of the Reverb.
The remote activation lever for Reverb attaches to the bar in one of two ways: using the discrete clamp or to a SRAM XX brake-and-shifter combo via the new-style Matchmaker X clamp. It can be mounted on the left or right side of the bars.
The Matchmaker X clamp and Xloc combination makes for one slick combination.
Reverb is designed for all-mountain usage, but the applications are pretty wide – from XC riders and racers all the way to freeriders and Super D racers, and everyone in between. Gram counters won’t be into the Reverb due to the 250g +/- penalty over a standard post, but riders who want to improve the experience and get the most out of their time on the trail won’t worry about the slight weight gain. If you are concerned about it, run lighter tubes or a different set of tires to drop some grams.
The best thing about the Reverb as far as I’m concerned is the hydraulic activation, particularly for people who ride in wet conditions. Changing shifter cables a couple of times a year is already a pain, and having to change the cable on your HA post as well is another hassle most riders can do without. The benefit of smooth operation year-round is hard to overstate.
Reverb is also supposed to be very durable. According to the RockShox engineers and product managers I spoke with, they have yet to have a hose rip out of the post. Some people may scoff at that, but think about it – when was the last time you ripped the line out of your disc brakes? And f the hose is somehow torn out, the seat will stay at the height it’s set at rather than sliding down.
Another knock against HA posts is cable movement or excess cable when the post is compressed. I didn’t run into any issues during my test ride and didn’t even notice the extra hose. I’ve also seen some comments online about moving the attachment point for the hose to the seat collar assembly, but that would a much more complicated (and possibly less durable) design as oil flow would be controlled in the middle of the post rather than the top.
This is what the whole assembly looks like out of the box. One little piece of equipment is going to change the riding experience for a lot of people.
During the short test ride I had on the Reverb, I came to appreciate the benefits of a HA post very quickly. I was able to ride uphills with the post extended, downhill with it compressed, and move it up and down very easily for rolling sections of trail to find the perfect height.
The handlebar-mounted button makes operation simple and promotes use over an under-the-saddle lever, and I found that I was using the post every time the terrain changed in order to improve the ride experience. Once you start using it regularly, you’ll discover other added benefits, like being able to drop the saddle on the trail for technical starts or at stop lights if you’re not into track stands. So easy, so quick.
The Reverb was very good, but it wasn’t flawless. At one point during the ride, the post failed to come all the way back up to maximum extension. That was because the seat clamp was just a little bit too tight, which deformed the post ever so slightly and prevented the internals from moving freely. Once the clamp was loosened, everything worked properly. According to Boobar, the post won’t have that problem if it is clamped to the proper torque specs. Engineers struggled to walk the very fine line between thick enough post wall and light enough weight, but production versions have been beefed up a little so this shouldn’t be an issue.
What did I think about the Reverb? Well, I’ve been riding mountain bikes in one form or another since 1990 and have seen a lot of new technology emerge in that time: clipless pedals, disc brakes, long-travel forks, lightweight all-mountain bikes. All of these things have been revolutionary in one sense or another, and they’ve all had significant impacts on the way I ride. They’ve made the experience of riding a mountain bike more enjoyable, and I have a feeling that the Reverb will as well. Stay tuned to nsmb for a full test.
The Reverb ships with the cable, the Xloc remote with handlebar clamp and a seat collar clamp, so you can ditch your quick release. They’re set to ship in September 2010, and will set you back US$299. RockShox is still working on Canadian pricing (likely due to wildly fluctuating global currency markets).
Like what you see here? Want one of your own? Think that HA posts are for people who don’t know how to ride steeps? That’s what the board is for.